Abstract 2740: High-throughput and sensitive quantification of circulating tumor DNA

Abstract

Abstract Circulating tumor DNA (ctDNA) has a great potential to serve as non-invasive biomarkers for monitoring disease progression and treatment response. However, its broad clinical applications have been hindered by sensitivity, throughput and complexity of existing ctDNA detection methods. Here we report an adaptation of a multiplex PCR pre-amplification (PreAmp) into the microfluidic multiplex PCR (MMP-Seq) technology for high-throughput and sensitive quantitation of ctDNA. We have demonstrated that PreAmp MMP-Seq enabled sensitive (down to 0.6% allele frequency), reproducible (R2=0.97), accurate and quantitative mutation detection from as low as 1.6 ng DNA input. An Empirical Bayesian Model has been established to estimate background error rates for every base of amplicons in the ctDNA panel using data from 43 normal plasmas. 0.1-0.3% of median error rates were observed across all positions. 149 longitudinal plasma samples from 12 ovarian and 10 pancreatic cancer patients of PhI DMUC5754A anti-MUC16 ADC trials were then profiled using PreAmp MMP-Seq. 79% (11/14) driver mutations found in tissue samples were also identified in matching baseline plasma samples at frequencies well above estimated error rates. Moreover, we found that changes of corresponding ctDNA concentration in post-treatment plasma samples were correlated with changes in tumor burdens and circulating protein marker levels. In conclusion, the MMP-seq PreAmp workflow provides an inexpensive, reproducible and flexible solution for mutation detection in plasma DNA samples. Citation Format: Yinghui Guan, Oleg Mayba, Shan Lu, Thomas Sandmann, Younjeong Choi, Walter Darbonne, Vincent Leveque, Lisa Ryner, Eric Humke, Nga W. Tam, Sundari Sujathasarma, Anna Cheung, Richard Bourgon, Yulei Wang. High-throughput and sensitive quantification of circulating tumor DNA [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2740. doi:10.1158/1538-7445.AM2017-2740